This is a co-pending application, related to Weisgerber, Motion Picture Production and Exhibition System, application Ser. No. 07/228,495, filed Aug. 7, 1988. The parent application discloses a multicomponent system for variably producing a high-impact, picture-dominance effect on motion picture audiences in a manner compatible with existing motion picture photographic and projection equipment and in a configuration that can be installed in a conventional motion picture theater. The system disclosed in the parent application also produces the picture-dominance effect in a manner that permits switching the effect in or out of the system, alternating between conventional and high-impact experience as an aid to advancing the story line of the motion picture.
As part of the overall picture dominance system, it is necessary to change film speeds during the film presentation. This is a part of the selective introduction of the high-impact effect, which is modulated during a single film presentation to expand the creative control of the filmmaker by engrossing the audience in a high-intensity experience during parts of the film and withdrawing into conventional film experience when the high-impact mode is not required. In addition to a transition from 24 to 30 fps, there are other events accompanying the transition; an increase in screen brightness and the expansion of viewing area by moving the four masks that surround the screen to expose more viewing area.
The system disclosed in the parent application is not the only application departing from the conventional frame rate of 24 fps. The rate of 24 fps became standardized during the early history of film when the early rate of 16 fps (projected with a triple-bladed shutter) gave way to the new speed of 24 fps, shown with a double-bladed
shutter. The standard of 48 impressions per second was maintained, and the frame rate of 24 fps has remained the standard within the industry, to this day.
It now appears that a new frame rate of 30 frames per second will soon gain ground within the industry. There were early experiments with the 30 fps rate; Oklahoma and Around the World in Eighty Days were shot in both 24 and 30 fps versions. The 30 fps rate has other advantages, as well. It is compatible with the NTSC television standard of 30 frames (60 fields) per second, roughly comparable to a film shown at 30 fps with a double-bladed shutter. The 30 fps rate also has significant advantages for viewers in the audience. Film grain and flicker are reduced, and the 30 fps rate provides smoother interpolation of motion, since the increments of motion as actually photographed are closer together in time. The reduced flicker also allows increased screen brightness, up to 25 foot-lamberts. As disclosed in the parent application, the rate of 30 frames per second has significant advantages over the conventional rate of 24 fps. These advantages have been officially recognized. See Di Gioia: Final Committee Report on the Feasibility of Motion Picture Frame Rate Modification to 30 Frames/Sec., SMPTE J., May, 1988 at 404.
There have been other efforts to introduce new frame rates. The SHOWSCAN system (Trumbull, U.S. Pat. Nos. 4,477,160 and 4,560,260) teaches a conventional 70 mm format, projected at frame rates in excess of 50 fps, preferably 60 fps. This high rate has the advantage of delivering an extremely smooth picture presentation, but it is not compatible with conventional equipment, which cannot operate without undue wear and tear on both projector and film, due to high speeds of projector operation and film travel. The 30 fps speed still gives the viewer 60 impressions per second without the drawbacks of SHOWSCAN.
With the likely appearance of 30 fps as a new standard projector frame rate, it will be necessary for exhibitors to switch between 24 fps and 30 fps operation within the course of an evening's film program, if not between scenes or sequences within a single film. It should be noted that, while the description of the current invention will refer to the 24 and 30 fps frame rates, other frame rates can be substituted and the principle disclosed will remain the same. An objective of the present invention is to provide a means for transition between frame rates, within the context of a single motion picture, encompassing an operation (or set of operations) that are completely automated. It is a further objective of this invention to provide a means for interpolating films of both speeds into a film program, without going through the steps required to change speeds manually.
The overriding objective of the invention is to create an experience for the viewers of the films shown that will not distract the viewers with artifacts that "remind" them that the film speed is being changed. The present system is designed to minimize wow and flutter, artifacts that often accompany a speed change. The system was designed as part of an overall system for exhibiting films in which a high-impact experience (picture dominance) is presented to the audience for certain portions of a motion picture and withdrawn, for a return to conventional film experience, at other times. In other situations, however, it will be necessary to change frame rates. A trailer for a film recorded in the high-impact system can be incorporated into a "conventional" 24 fps program. Films shot at 30 fps can be shown immediately before or after films shot at 24 fps. The storage of an entire evening's program on one platter and automatic transition between film speeds will simplify motion picture theater operations, while delivering an improved experience to the audience.